I would be interested to learn what sort of assistance a zoning officer is suited to provide to a fire department on a gas leak incident. From Darien's website, the zoning officer is also the code enforcement officer. Perhaps his role is to close the property until the leak is fixed and system reinspected? Certainly the fire department would at least have authority to evacuate a building initially. If anybody knows about these things, please let me know.
It's surprising that the business would ignore evacuation instructions for a full 30 minutes, apparently knowing there was a serious gas leak warranting emergency response.